All posts by Blackthorne

Why batteries are the ultimate power supply (for low level signals)

shoots!  might as well build up another pre-premamp that uses 9V batteries while i’m at it.  i know for a fact that this is a perfect match for the Denon 103R moving coil cartridge, which has been in production since 1961 and still available and highly revered today .  part of the pre-preamps magic is the independent power supplies for the right and left channels from the 9V batteries.  we are talking milliamps of amplification, so the batteries actually last for months and are an extraordinary stable power supply and it this makes it cheap to make since no AC to DC conversion or power regulation circuitry needed.

I already knew my Denon 103r cartridge was gonna be magic with Maggie’s cause I had run the combo before in the 70s and it was the best quality playback I had ever heard, bar none. SP 10 deck with Decca tonearm with 103r cartridge into a prepreamp I built myself that ran on 9v batteries, dual mono design and very accurate power supply for low level signals, into a AofO preamp into a couple CC-2s bridged as mono blocks. They have come out with better power amps for Maggie’s since then, like the PA-7, but my Kefs still LOVE my CC-2s…

The music we will never get to hear.

Talk about The Cure Disintegration on vinyl.

ok… so this guy and i are obviously singing the same tune.  maybe cause we were both into it during the “golden age” of hi-fi (the late 70s), and both worked at AofO at that time (BTW- where he mentions Sony/DSD he is referring to SACDs):

“full credit must be given to companies for Sony/DSD and dCS upsampling, but what’s the point of wasting 20 years to end up right where we started?

This time, though, unlike the solid-state fiasco, we leave behind a legacy of 20 years of low-resolution 44.1/16 digital recordings. It’ll take some pretty fancy fractal-analysis technology to add resolution that simply isn’t there in the data storage medium. Those bits fell on the floor during the first A/D conversion, never to be recovered, only guessed at by clever computer algorithms many years later. “

http://www.nutshellhifi.com/library/tinyamps.html

Why do my speakers have spiked feet?

Spikes are clearly acoustical couplers (that’s why you want them on the bottom of your speakers), so why would I want to couple the upper platform to my TT you may ask?…  Well, by doing so I effectively increase the mass of my TT plinth by 9 pounds whilst the entire thing is isolated.  And, by virtue of their design they act as mechanical diodes (one way valves) to remove any mechanical vibrations from my TT motor away from my stylus (page 406).

The acoustic adventures continue…

 

More later…

Self Powered Speakers

PurityToIPODwho better to design an amp perfectly to drive their speakers than the speaker manufacture themselves.  i had some self-powered bookshelf speakers back in the day that were simply amazing!  the beauty would be simplicity and cost savings, the down side if if the amp blows or the speaker element blows, you gotta fix it or you loose both your speakers and your amps at the same time.

More on self powered speakers later…

The Classically Mis-matched High End Audio System

I often witness the “classically mis-matched” high-end audio system.  It is very, very typical, where part of the system gets upgraded but that can lead to more of a highlight of the deficiencies of the other components and the net effect can actually be negative.
Say you upgrade speakers and amps that are ideal for your room acoustics and place them just so for your sweet spot.  That that means is you will hear all the good, bad, and ugly of your sources or anywhere else in your may have a deficiency .  This is fantastic if your sources and signal path is up to the task but can be revelatory (and not always in a good way) if they are not.   I’ve witnessed many an aspiring audiophile repeatedly upgrade speakers or amps because they must be at fault when in fact they are just hearing the faults in their system revealed for the first time due to better reproduction accuracy  the new speakers revealed in the first place.

The most obvious difference between 2 channel audio and 5.1 home theatre.

My experience with surround sound (usually found in audio systems for home theatre) is that it relies greatly on the centre speaker to create the sound stage.  This is obvious for movie sound tracks, but also prevalent on surround sound music mixes, such as those found on SACDs and DVD-As.One of the real benefits of  digital surround sound is that it can combine both the highest digital quality available along with amazing 5.1 surround sound mixes.  A win/win for anyone who has longed for more than just two channels to present the music with.

But traditional ESLs (electrostatic loudspeakers), such as the venerable Martin Logan Sequels and the Sequel IIs, were a product  of 2 channel stereo sound reproduction.  They were never intended to be part of surround sound speaker set.  Not that they wouldn’t be great at it, just that the nuances of the sound stage they have been designed to create would certainly be lost once you throw the centre speaker into the mix, which pretty much destroys any intended 2 channel sound stage anyway.

This isn’t all cons, however.  In very difficult rooms or where the rooms esthetics trump the ideal speaker placement, a centre channel can serve to save the day.  But with good room acoustics and  a reasonable option of placements for ESLs, a pure two channel signal path will reproduce a more engaging and intimate soundstage every time.

Acoustic isolation for turntables – to couple or decouple?…

This is a "sprung" turntable
This is a “sprung” turntable

This is a trick question since the answer is often…  both!

Ok, so most audiophiles know that the “big bad wolf” of turntables can be acoustic feedback.  Simply put, this is where the speakers vibrate the floor, walls, air (and hence dust platter) and that vibration gets feed back to the stylus and amplified then sent back to the speakers where it causes more vibrations to be amplified, and so it goes.  You get the idea, the classic positive feedback loop.

This is the “big bad wolf” since if it runs out of control, which undampened positive feedback loops do by definition, it has the potential to destroy speakers and even amplifiers.  So how to you test for this in your all analog vinyl signal path?  It’s really simple.  Place the needle on a record that isn’t spinning and turn up the volume (very carefully!) until you start to hear a howl then immediately back it off from there.  That’s your acoustic feedback threshold.  If this is well above your normal listening levels or not there at all, great you have nothing to worry about.  If it’s within your listening range, you’ve got some isolation work to do.

So most already know that turntables deal with acoustic vibration in one of two ways: acoustic suspension or “sprung” turntable platforms or very heavy and solid plinths that use the physics of “mass loading” to deal with it.

 

On thing has become obvious, my system rack which consists of an teak shelving unit open on the front and back, is about the worst case scenario for this “component”. Rather than isolate it serves to amplify rumble. This is the type of thing that isn’t glaringly obvious but rather a welcome absence when it is gone.   My solution will most likely be a wall mounted shelf as virtually no rumble can pass from my concrete slab to my wood framing.  A very inexpensive solution available to me since I’m on the ground floor of a dwelling constructed as slab on grade.

 

“Generally, mass coupling works better for heavy components, and decoupling for lightweight components”, p. 406

I’m lucky since my speakers are sitting right on top of my ground floor slab contributing to fantastic bass.  My challenge is the opposite, to decouple my turntable.

You have several challenges in that department. Biggest is being on the second floor and on top of resonating floor joists. Many people in this situation cross block and other renovations underneath to address this if they are above a basement where the framing is easily accessible.

In your case you need to endeavor to couple your MLs to the sub floor. You have a nearly worst case scenario right now if you are still running them without any feet, not even the ones provided by ML. This is a very important aspect of the speaker design and I’m hoping it has a lot to do with the lacking bass in your MLs…

Granite tombstones wouldn’t be over kill given your room challenges, but any very heavy object will serve to couple to the floor, then just put your MLs, and maybe your power amps, on top of that.  It’s either that or spike your wood floors…  Not. Spikes on a penny will help, but i suspect its a half measure. Try it first, it’s cheap 🙂

 

Actually, mounting the shelf to the wall went very well.  Too well.  My first instinct was to hang it off the drywall and thereby be more isolated from the studs and therefore the floor where my speakers stand.  So I got some drywall anchors rated for 80 pounds and started down that road.  Hence the two unused holes in the wall you see in the photo, anchors actually, I just left them there.

It became immediately apparent that the dry wall anchors and brackets couldn’t handle the weight of my Denon and the two very heavy wood slabs I’ll be using as an isolation platform: 30 + 9 +9 = 48 pounds.

No worries… I go to Home Depot and get some uber heavy duty shelf support brackets, secure them 3 inches into my studs with 3 x  5/8” lag bolts per bracket, then set the wood platform and Denon on that.  Rock solid.  I could stand on one of those brackets and it wouldn’t sag or pull out from the wall one mm.

So I grab a record (APP I Robot), do my routine, then set the needle down in eager anticipation.  The first thing I notice is what’s not there… No more surface noise.  Gone, dead quiet as the needle touches down and I’m thinking, “Wow… this is gonna be good”.

Then, as the music kicks in I get immediate acoustic feedback.  I had a hand on the volume control and it was a good thing as acoustic feedback forms a positive feedback loop that can rapidly run out of control and start destroying speakers and power amps.  I’m like…  “bummer” as I play with the PFB loop and notice exactly where it starts to run wild and I turn it back down.

So, I almost directly coupled my Denon TT to my speakers through the floor (the Kefs are obviously very well coupled, a very good thing) to my studs to my shelf to my TT.  My teak rack may be creating other vibrations, but it is very effectively sheltering my TT from the “big bad wolf”, runaway PFB.  Oh well, live and learn.  I was planning for my TT isolation method to be three fold – shelf combined with first stage isolation (rubber isolators and a bike tube between the very solid and heavy wood shelves) then finally direct coupling with spikes of the TT plinth to the upper wood shelf, to take the TTs internal vibrations away from the needle.

Stage one, the shelf, clearly isn’t working, by itself anyway.  gotta wait for my spikes, isolation pads, and bike tube to show up before I experiment more.  Until then, it’s back to listening to pretty amazing analog sound quality, with a little cabinet resonance in the mix.  It’s subtle… something you notice more by virtue of it’s absence than its presence.

 

Spikes are clearly acoustical couplers (that’s why you want them on the bottom of your speakers), so why would I want to couple the upper platform to my TT you may ask?…  Well, by doing so I effectively increase the mass of my TT plinth by 9 pounds whilst the entire thing is isolated.  And, by virtue of their design they act as mechanical diodes (one way valves) to remove any mechanical vibrations from my TT motor away from my stylus (page 406).

The acoustic adventures continue…

More later…

What is Blu-Ray Audio (BD-A)?

A new high definition audio format
A new high definition audio format

looks like BD-A is but a grass routes crusade at this point.  yeah, right… don’t hold your breath.

having said that, i’d pick up any titles by artists you like that appear.

BTW, this (BD-A) is a dumbed down version of SACD and DVD-A.

DVD-As are already doing 192kHz/24 bit sampling rather than just 96kHz/24 that BD-As are.

SACDs do one better with one bit DSD sampling.  Techy jargon, but I’ve got some music on both SACD and DVD-A (Fleetwood Mac Rumors, Eagles Hotel California) and the SACDs definitely sound much better, even on my modest system.  With what you’ve now got going on, the differences will be far more dramatic.

So… bottom line, with BD-A at only at 96K/24 bit, I’m not holding my breath for good audio.  Better than CDs?…  Absolutely, far better in fact.  But still a full notch below DVD-As which are already a full notch below SACDs.  Remember that the buck stops (or begins) at the quality of the source.  Crappy source and all the gear in the world will just get more glorified crappy music.

The benefit of BD-As of course is that they will be playable by anyone with a BD player, which is most everyone these days.

 

Horizontal bi-amping with non-matching amplifiers

Wiring for horizontal bi-amplification
Wiring for horizontal bi-amplification

Horizontal Passive Bi-Amplification
Horizontal bi-amping allows you to use two different types,
models or brands of amplifiers (i.e. tubes on top, transistor
on the bottom). However, we recommend that you use
two identical amplifiers (i.e. same brand and model).
If you must use two different amplifiers, it is essential that
they have the same gain or that one of the two have adjustable
gain so that you can match their gain characteristics.
If the amplifiers of choice do not have the same gain
characteristics, then a sonic imbalance will occur.

For non-matching amplifiers:

since the loads your adcoms present to the Onkyo are 50K ohm and 100K ohm, which should present a load 33.333K ohm load to your pre-amp, which should be easily driven by it, assuming the output impedance of 470 ohms specified in the manual for your record outputs (rec out) on your Onkyo is also put out on your pre-outs.  It doesn’t specify for the pre-out, so fingers crossed that it’s about the same as your record outs.  the quality of tour interconnect cables and splitters will likely have a great effect on impedance than your mismatched amps.

see this link for how to calculate impudence for dissimilar loads wired in parallel (this is in a perfect world. it’s actually WAY more complicated than that, but this is good enough for what we are up to):

http://www.sengpielaudio.com/calculator-paralresist.htm

 

ohms and calculations aside.  think of it in these simple terms…

you will be splitting the signal from your Onkyo L and R front pre outputs and sending it to two amps instead of just one.  so think of it as now “driving” two amps instead of just one.  this puts a far greater load on your pre-amp.  most audiophile quality pre-amps are designed with this in mind.  but AVR receivers with pre-outs as an add-on or even an after-thought…  not so much.  don’t get me wrong, i think your Onkyo will drive your amps just fine.  but we want to do everything we can to make it easier.  this includes:

– high quality splitters
– high quality and as short as possible interconnects (that’s why i like the stubby splitters, why add more cable into the equation if you don’t need to)

to insure against any hum, you will want to place your pre-amp (Onkyo) at least 6” away from your adcoms, preferably on a different shelf.  if you can still get away with 3’ interconnects, that would be best.

More later…

Just say “no” to HDMI

HDMI

When I discovered Oppo isn’t supporting component video out on their players I immediately called foul:

http://www.oppodigital.com/blu-ray-bdp-103/blu-ray-BDP-103-Images.aspx

While I don’t consider myself a videophile, I know from direct experience with my home theatre system that component video provides far better video quality than HDMI does.

my thought was to wait until Oppo comes out with a 4K player (NOT just an up-sampling unit but one that can play 4K when the media becomes available) then grab one as their players almost always support SACD and DVD-A with analogue 5.1 outputs (thankfully still there).

they have been know as being the low end of the high end for some time in the audio world, with good quality, discreet DAC’s.  anything more than what they have to offer would be overkill on the system i have now, and i would venture to say that it’s possible it’s even overkill for that even, though without doing an A/B i wouldn’t know.  The primary part of an SACD player that will make an audible difference is the DAC.  Second, and a distant second, is the quality of the transport.  At the high end of the high end, these are separate units.  And… even at SACD quality, it will never touch a good 2 channel vinyl system anyway so why bother.

i’ve never paid to much attention to their video side of things, and i guess neither have they if they are capitulating to HDMI output for video signals.

players with component video outputs may become more and more rare.  I was sadly disappointed when HK left any and all audiophiles behind by no longer supporting analogue 5.1 inputs.  i’m sure videophiles feel the same way about the loss of analogue component video support.  my experience in both audio and video is to let the DAC happen once, at the source with good quality DACs, then go all analogue from there for best quality.  or, in the case of vinyl, never let the signal path be downgraded by a ADC digital conversion in the first place.  Analogue the whole way.  Don’t think think you will find any argument there from those who are particular about sound quality.  Of course the “techies” love to banter the arguments around, but that’s cause they like to hear themselves talk (or type).

remember, there are two kinds of audiophiles, those who love the music and those that love the gear.  the latter tend to love all the whistles and bells that digi offers.  but you will see the former seeking out the simplest gear capable of the purest sound reproduction possible (these things are mutually inclusive, simplicity and pure signal path).  and their true treasure will be their collection of music.  after all, the equipment is replaceable but the media (be it vinyl, SACD, Blu-Ray, 4K or whatever)… perhaps not. (think of the movie “V for Vendetta”)

i would venture to say the same is true with videophiles as well.

fun that we are both getting back into this!

mark

Why bi-amping isn’t always what you may think

BiAmping

Bi-amping used to be the sole providence of high end audio.  I’m therefore suprized that many modern mid-fi speakers have the ability at all.  But, as long as it’s there why not play around with  and see if it makes any difference.  Most modern, higher end 7.1 AVRs also have the ability to utilize the “surround back” speakers to another zone or to bi-amping your front speakers if you like.

That said, we are still talking about a very different version of bi-amping from what i knew it to be in the 1970s, i.e. passive rather than active.  The good news is that passively bi-amping just requires removing jumpers (or “bridging plate”) and hooking up directly to the binding posts on the speakers and let’s the speaker manufacturer decide what happens from there.  Less control, but also less ways to screw it up if the listener doesn’t have knowledge of speaker crossover networks.

Active crossovers (XOs) require some basic knowledge of speaker design, crossover designs, and the limitations of the individual drivers.  I built up a small pair of speakers in the 70s with Kef B110 bass drivers and T27 tweeters.  I was building off a schematic but tweaked the parts of the passive crossover network with better quality than what the manufacturer (they were Rodger’s LS35A’s) provided and they sounded AMAZING and i saved a ton of $$$ by buying the drivers separately and building them myself.  As a side note, those 70s speakers (from the manufacturer, not my home-made version) have become highly collectable and I’ve seen them advertised for up to 10 times their original selling price of $400, which was high  at the time.

 

What is DoP (DSD over PCM)

DoP

When I first discovered that this was the only way to transmit DSD files from an Apple computer to a USB DAC I was dismayed.  Buy virtue of the name itself I thought that the signal must have to be converted to a PCM signal and that would rain on the parade of native DSD goodness that has revived the world of high quality digital music.

Well, very thankfully that wasn’t the case.  The signal remains native DSD, it is just packaged up differently in order to be transmitted.  No PCM conversions are made.  Without going into technical details, think of it like this.  A 24 bit 384k PCM signal path is capable of transmitting (? MB/sec), so think of that as a very large pipe.  The DSD signal is in fact a far smaller pipe at ? MB/sec, so all that is done is to get the signal to flow inside this larger pipe.

More later…

Subwoofers

SubwooferCutAway

Matching subs to speakers has a lot of chatter on the forums since it is requires the listener to get involved to get it to sound right.   Often subs are matched to front speakers of a different manufacture, which means the speaker designers aren’t in the loop as to how things go.

Ultimately, it is up to the listener to “tune” the sub which would be a difficult task if you try to do it technically, with cross-over curves and such.  but… it’s really easy to do for a trained ear when you know what to listen for.  I just set the phase correctly (immediately obvious when you toggle the switch) then play with the volume and low pass cross-over setting until it sounds right.  I often adjust it differently for different sources.

thought i’d elaborate on the “.1” of 5.1” sound.  (since it comes up so often by the techies).

firstly, it puts the speaker designer out of the loop, so the user needs to pay close attention to how they mix and match subs to the rest of the speaker system.

so…  when you are talking about digital audio outputs (HDMI, digi Coax, Optical), which almost everyone is these days, what happens to the .1 becomes a matter of great debate.  The techies love this kind of stuff, and spend more time dwelling on it than actually listening to music and/or watching movies.

but… when we are talking about analog audio 5.1 outputs, such as is the case with SACDs (some at least, see below), the decision as to what is going to your subwoofer has already been made when the audio was mixed.  the sound engineer doing the recording did it, and almost certainly did it far better than any of the digi techies could ever dream of.  of course, you still need to tune your subwoofer to your system, but what content it is getting is nice and clearly decided for you.

that’s why i suggested you try your ML’s both ways, with and w/o the sub.  To understand why, consider that there are three types of SACDs:
1. SHM Stereo only (like my Japanese imports)
2. Hybrids that have a “Redbook” CD layer (44.1 kHz sampling) and an 2 channel SACD layer (like all of the MFSL Original Master recordings)
3. Triple Layer that have a Redbook CD layer, 2 channel layer, and a 5.1 surround mix layer (these are the ones that tend to become collectable when they go OPP since the only version of that 5.1 mix that exists in this universe is on them)

I think when you play the 2 channel only versions, it’s quite possibly they will sound better by letting the MLs, bi-amped, handle the entire job by themselves.  Otherwise, you need to get in the middle and decide how you want the subwoofer to behave, crossover, etc for the 2 channel sound.

But.. when you play the 5.1 mixes, the sound engineer (but this is beyond engineering, and an art in of itself) in the mixing room will have decided what content goes to the sub already.  you just hook it up, tune it a bit according to the type of sub it is and personal tastes, and let the magic happen 🙂

having said all this.  i think it’s time to just have some fun listening to your music collection again.  you are already way ahead of the game just as things are now.  i just LOVE listening to music and the real pleasure that I get from adding of upgrading gear is not from the technical aspects, but from how i can rediscover my music collection when i do.  for example. i’ll try a different phono cartridge and… assuming i like it better than what i had, want to listen to most of my music again before i change a single other thing.

all your CDs are gonna be a fun experience in rediscovery just based on how things are now. enjoy getting to know your music again.  or for the first time.  you could spend months just rediscovering your existing music collection.  it’s really fun to pick up the differences and develop your personal tastes along the way.  then you will really pick up some of the other improvements when you add an Oppo (even just to your existing CD collection) or start picking up a few SACDs…

It’s all about the music… (not the gear)

After 38 years in audio, I’ve come to a few conclusions.  They are of course, my opinions:

Pay attention to the people who love listening to music and therefore do reviews on gear that does it best, not the techies.

Pay particular attention to reviewers who like the same music and have similar taste as you (or better still, do lots of critical listening and form your own preferences)

Don’t forget to take your reviewer’s hat off once you are satisfied and enjoy the music again, it’s the reward!  Over several years in the late 70s I ended up with the ultimate system (for me), then I fully relaxed and looked for new music to experience and enjoy.  My reviewer’s hat was off for good at that point.

Upgrade only one component in the signal path at a time and listen to a lot of music with the upgrade before moving on.  How else can you really appreciate the difference?

Collect music, not gear.  I’ve seem countless rooms full of audio gear rather than music.  I’ve even seen listeners fill their rooms with components. to the point where the room acoustics are compromised, and only have a dozen or so albums to play.  The only reason to have a redundant component in your system is if you are auditioning that part of the signal path for a possible upgrade.  Otherwise it’s money spent that is just collecting dust and could be spent on more music to enjoy.

Match your gear to your wishes.  Do you sit down and listen to music or do you watch movies where the sound takes second stage?  What kinds of music do you listen to?  What kind of movies do you watch? If you’re really into movies, then did you know details like is kacy duke in inventing anna a man?

Match each component (including your room) in the signal path to each other.  Your music can sound worse with a better quality reproduction system if the quality of the source is inferior, for example.  Now one is just hearing more of the original deficiencies. Do comparison tests to find your weak spots.

What about mass market DVD players for audio?…

A nude photo showing discrete analog circuitry for each channel.
A nude photo showing discrete analog circuitry for each channel.

Many mass market DVD and Blu-ray players are capable of playing high-def audio, such as SACD (most Sony players have this capability since they invented it), DVD-A, and Blu-ray Audio.  So how do they perform in a high end audio system?…

When looking at the  signal path in these players, it boils down to three things, which you won’t typically find in the  specs of mass market players (they wouldn’t be, since they aren’t really intended to play high end audio).  These three things are, in order of their importance to your audio quality:

1 – D to A converters, also known as DACs.  You want good quality DACs in your player, get it to output the analog signal (on RCA or XLR jacks), then get everything downstream in the signal path to leave it alone as much as possible (beyond amplification of course).  That’s one of the many reasons why HDMI rains on the parade for a high end audio signal path.

2 – Discreet analogue signal path for all channels once the signal has been converted to analogue by the DACs.  Take a closer look at the inside of the Oppo BDP-95  (which is not a mass market player) and you will immediately see what i am referring to).

3 – Transport mechanism.  Pretty hard to screw this up too dramatically, but the higher end players make certain this is of the highest integrity so the digi info on the discs is read with as much accuracy as possible.  Other’s fudge it with some sort of error correction protocol, such as parity.  They recognize that there will be a certain % of errors reading the disc so they have algorithms to correct for that. Obviously, it is better still if the laser reads with as close to 100% accuracy as possible.  The higher end units separate the Transport and the DACs into two components.  very pricey of course, and the cost isn’t warranted by a digital sourced signal path IMHO, especially for CDs.  Like I said, garbage in, garbage out… what ever else is claimed.  But there are many who would beg to differ, until recently at least.

Haufe SUTs – SOLD

Custom made two channel SUT using famous vintage HAUFE transformers from the 60s. Step up ratio is 1:40 and gain is +32 db. NOS audio transformer are mounted into a new aluminum case. All connections are wired to gold plated RCA jacks. Dimensions 5.3″ by 4″ by 1.5″ high.

These are perfect for LOMC cartridges and I used them for my Denon 103R but no longer need them since I purchased an ARC SP9 MkII which has plenty of gain in the phono stage for my 103R.

Haufe, of course, is famous for having manufactured the audio transformers used in some of the finest vintage high fidelity and professional german and european audio equipment, including Telefunken/Siemens recording consoles, Klangfilm theater equipment, etc.

Thanks for looking,

Mark

Denon DP-790W turntable review

So I’ve owned and cherished this vintage turntable for over a year now.  It’s circa 1978 and I purchased it in absolute mint condition from a very friendly and interested budding audiophile in Calgary.  I drove there in -20 degree weather to go pick it up.

I’ve upgraded the phono cartridge with my beloved Denon 103R.  That is in fact, a big reason I purchased it, since I knew the tonearm compliance is a perfect match for my favourite LOMC (Low Output Moving Coil) phono cartridge.  I’ve also always preferred direct drive turntables to belt driven ones.  Yes, I know that will open a can of worms that I’ll address in another post (Turntables – Direct Drive vs. Belt Drive), but I will always remain an advocate of direct drive turntables ever since owning one of the finest direct drive turntables ever made, the Techniques SP-10 MkII back in the 1970s.  And when searching for a mate for for my Denon 103R matched to the Nelson Pass phono stage found in my Nakamichi CA-5A preamplifier, this was an obvious choice.

I carefully packed it to travel as checked baggage on my flight to Maui (How to pack a vintage turntable) and when I unpacked the box I was pleased that the precautions I had taken resulted in safe passage.  Needless to say, high quality audio gear is neigh on impossible to find on Maui.  So I imported.  

It took me a while to set it all up since it had been years since I had properly set up a turntable.  Azimuth, overhang, accurate stylus force, leveling, VTA, cartridge loading, were all tweeted (How to set up your turntable for your phono cartridge).  Then, I found this otherwise fantastic turntable’s achilles heel.

Virtually all turntables use one of two methods to deal with acoustic feedback (vibrations from the speakers returning back to the phono cartridge to be re-amplified in a positive feedback loop), either suspension (sprung turntables) or mass loading (Acoustic isolation for turntables – to couple or decouple?…), and this one has neither.

The plinth, while solid, is certainly no example of mass loading, but it also lacks any form of suspension.  The only attempt Denon made at acoustic isolation were four grossly inadequate rubber feet.  Thus began a quest that lasted weeks – how to isolate this otherwise exemplary turntable.

It was immediately obvious that vibrations from my “equipment rack” (which is an ordinary teak shelving unit that is almost seemingly designed to mechanically amplify vibrations but I like it’s esthetics and know I can do what it takes to modify ordinary furniture to my needs, right?) would be a deal breaker.  No problem I thought, just hang the turntable off the wall so that’s exactly what I did and expected good results.  Not.

The trouble was the tight bass of my Kef 104/2s was so well coupled to my wood-over-concrete slab floor (coupling is exactly why the bass is so tight) that it transmitted very efficiently and effectively to the wall studs from which my precious turntable was hanging.

What ensued was a methodical study of acoustic isolation techniques.  I didn’t really want to re-plinth the deck, it is a frigging perfect example of it’s original glory (or lack thereof in the isolation department).  So I experimented with various methods to build an isolation platform for it to sit on.  I started with a couple pieces of the hardest and densest wood I could find (they almost feel like granite they are so heavy) then various methods between them in the form of ball bearings (which virtually eliminate horizontal vibration transfer – they now sit under my power amplifier), bicycle inner tubes (don’t over-inflate or it defeats the purpose), Sorbothane feet, spikes (coupling the extra mass to the plinth), and every combination thereof.

What I ended up with is three (in order to offset them from the four feet of the turntable plinth) Vibrapod cones, stacked into three Vibrapods that are rated for the weight of my turntable between the two massive wood platforms, a bicycle  inner tube directly under the platter assembly with a straw to let it breathe, along with four Sobrbothane feet under the original feet with reasonably good results.

“Reasonably good?!” I’m sure many of you are asking.  Anyone who knows me or reads this blog knows that “reasonably good” is far from good enough.  So the quest continues.  I plan to further experiment with granite slabs and boxes full of sand (Maui beach sand of course) before I feel I have fully exhausted acoustic isolation techniques.  I might still hang the platform from the ceiling but I’m hoping to not resort to such drastic measures.  And that’s certainly part of the fun, discovering what works and what doesn’t.

I presently have the acoustic isolation tamed to where it is below maximum listening levels, but barely so.  If I “crank it” on some of my fav music that, well… I just love to “crank it” on I’m sort of “dancing with the acoustic feedback devil.”  Still… in spite of all my methods.  Under the limits test – phono cartridge sitting on non-spinning vinyl, it is unquestionably still there, and rages out of control a mere notch or two above my maximum listening levels.  Of course, it’s drastically reduced on spinning vinyl since that presents a “moving target” for the positive feedback loop to occur.

So what started as a turntable review has evolved into a study of acoustic isolation.  As for the rest of the turntable attributes?…  It is the perfect example of everything I love about direct drive turntables: massive platter, precision speed control (not tied to the frequency of the power outlet as are so many of the lessor belt drive turntables), and virtually non-existent wow and flutter.  Also, being that it’s fully manual, the gorgeous tonearm is like a separate component, and shares no circuitry or mechanics with the rest of the turntable.  The now upgraded (Time for new tonearm cable?) five pin DIN tonearm cable connects directly to my Nak CA-5A without electrical or mechanical interference of any kind, which is extremely important to me for obvious reasons.

Of course, this means that this remains a fully manual turntable.  You cue it up by hand and you get up and pick up the stylus at the end of each side of your vinyl or you are serenaded by that methodical clicking of the stylus on the run-out track.  And I wouldn’t have it any other way.  If you’re listening to vinyl you’ve already made the choice of superior sound quality over convenience.  If you play vinyl with an automatic turntable you might as well fire up your music server and indulge in the full-service (and compromises) that automation offers.

Does anyone else remember the turntables that used to stack multiple records to drop onto the platter in succession?…  Just load up a few records and you’ve got a vinyl iPod.  That was how it was done back in the 1970s.  That is, if not getting out the listening chair was more important than sound quality (and preserving your vinyl).

All-in-all, I couldn’t be happier with this turntable.  With Denon’s original direct drive technology, which arguably hasn’t improved since the “golden age” of vinyl, combined with around $100 to $150 spent on my DIY (do it yourself) turntable isolation platform, I have a deck to rivals that of $30k decks today.

Incredulous?…  Yes, direct drive turntables, which I’ve been “singing the praises” of for years are coming back in vogue, and selling for $30k.  Just have a look at VPI’s (a long time advocate of belt drive turntables), newest addition to their product line, a “classic” direct drive turntable starting at $29,999:

http://www.musicdirect.com/p-157642-vpi-classic-direct-drive-turntable.aspx

Postscript: December, 2014:  I’ve used a massive granite slab coupled to the Denon with spiked feet, sitting on a bed of sand in a nice wood box, that sits atop my existing double wood slab isolation platform and have finally accomplished the desired result.  Altogether, it weighs in around 150 pounds, which is hung off the wall by two very sturdy brackets.  Total cost of the modifications?..  Less than $200.  Total cost savings vs. purchasing a modern day equivalent of this turntable?…  At least $5k.

When DSD isn’t DSD

Ok…  so  most of you probably know that I consider DSD to be the best thing going in the digital audio world.  I came to this conclusion with A/B/C listening tests of reference quality source materials around 6 years ago and my initial conclusions have been reiterated time and time again.

Are all DSD recordings really that good?… Absolutely not.  There are still plenty of opportunities to screw things up and I’ve heard a fair share of DSD recording that have done just that.  With DSD, I can hear their mistakes, but 44.1k/16 bit PCM puts a veil over everything such that it really doesn’t matter anymore.

That said, a pure DSD signal path requires diligence to obtain.  You can have the best SACD player known to this world playing one of the best DSD recordings every made and, if you hook it up with an HDMI cable you are no longer listening to it in DSD.  That’s because HDMI converts everything to the ubiquitous PCM world to pass the signal off for DAC and subsequently analog amplification.

By the same token, you can be playing DSD files on your computer-based music server and still listening to the sonically degraded PCM version.  In fact, very few computers are able to perform a DSD DAC conversion, and none that are presently available (Sony once had that capability in their VIAO line of laptops, but they subsequently took it away as they did with the PS3).

So, how do you make sure you’re listening to a purely native DSD signal path?…  If listening to an SACD player you need to use the analog (usually RCA) outputs so the DSD DAC conversion happens inside the player (more on what to look for in a player in another post).  If you are running a computer-based music server you will require a native DSD external DAC, passing the DSD data off via USB.  Once carefully configured, it’s possible to use DoP (DSD over PCM which is a very clever way of passing of the DSD data fully intact for Mac computers – see other post) or ASIO for Windows, since Windows has no built-in audio drivers in the first place.

And… most popular SACDs have been tainted by PCM somewhere along the way.  Are they still sonically superior to their fully PCM equivalents?…  Yep. They just aren’t fully showcasing what an entirely DSD native signal path is capable of.  Most audiophiles haven’t heard a entirely native DSD signal path, and therefore many are non-plussed by it.  And, there are some recordings that have their best release in PCM.  “Riding with the King” by Eric Clapton and BB King comes to mind.  The PCM version sounds as good or better than the vinyl since the vinyl version was mixed in PCM anyway.  A fantastic analog recording, mixed in PCM then rereleased on vinyl obstensibly for it’s superior analog characteristics.  Can you say… missing the point?!

Same thing is true for the Cure’s “Disintegration”.  They even have a sticker on the vinyl jacket proudly advertising “Digitally Remastered”, which might as well read “Just buy the CD instead and don’t pretend you’re getting better sound quality from vinyl cause we already PCMed this one”.  Also true for Elton John’s “Goodbye Yellow Brick Road Digitally Remastered” vinyl release.  You might as well go buy the SACD and be one step closer to the already digitally degraded source.  Cutting a lacquer to press vinyl from a digitally mixed recording simply makes no sense, unless for nostalgic value rather than sound quality.  If they already PCMed this recording, than at least give me the 24 bit version but alas… no.  If you really want the analog goods, you’ll need to seek out a mint MFSL (Mobile Fidelity Sound Labs) Original Master version of this recording from when it was originally released in the 1973.

In order to truly hear what a fully native “Direct to DSD” recording sounds like, grab one of Blue Coast Record’s DSD downloads.  They have gone to great lengths to preserve the integrity of the all-DSD signal path.  Of course, they have also gone to great lengths to gather some very talented musicians and engineer fully acoustic studio recordings with some of the best microphones ever made (from the 1980s I believe).  Their attention to detail is extraordinarily obvious on a quality system playing their native DSD files w/o being PCMed along the way anywhere.

There are also some more ecletic SACD samplers, such as those released by LINN Records, that gather together a variety of artists and music styles to showcase what the DSD format is capable of when left alone to do it’s thing.  Unfortunately, most of the more popular main-stream SACD (therefore DSD) titles will have been PCMed somewhere along the way.  Do they still sound better than their fully PCM equivalents?…  Yes, consistenitly so.  But have they fully unleashed the sound quality available by DSD?…  Unfortunately not.

Maybe someday we’ll see audiophile re-releases of such titles where they are remastered on a fully native DSD signal path from the analog original master tapes.  As it stands now it’s a mixed bag.   Most of the MFSL DSD releases should be direct to DSD using a Sonoma DSD workstation to do so, as well as some of the more prominent titles such as Pink Floyd’s “Wish You Were Here” and “Dark Side of the Moon” (let’s hope so, with the likes of James Guthrie back at the controls).  But it still remains a “you know it when you hear it” kind of thing.